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Microwave Noise - RF Cafe Forums
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| Avalan
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Post subject: Microwave Noise
Posted: Wed Mar 18, 2009 11:21 am
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Joined: Wed Mar 18, 2009
11:07 am
Posts: 2 |
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Hi
I am a junior RF planner and just need
some guidance in a thought that a have. In a split
configuration microwave setup you have your ODU
up on the mast and your IDU down in a protected
housing right. Now if I want to calculate the thermal
noise I use
Nt = kTB
(k = Boltzmann, T =
temperature in kelvin and B spectrum bandwidth)
My problem, as the receiver sits in the IDU
should I use the IF bandwidth in the feeder as my
spectrum bandwidth or should I use the channel bandwidth
that is received by my antenna? Maybe I should use
a combination of both?
I figure you can't just
use the IF bandwidth as some thermal noise would
have already been added to the system by the amplification
of the antenna and ODU.
Does anybody have
some thoughts on this?
Thanks
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nubbage |
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Post subject: Re: Microwave Noise
Posted: Thu Mar 19, 2009 6:14 am
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| General |
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Joined: Fri Feb 17, 2006
12:07 pm
Posts: 304
Location: London UK
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Hi avalon A better approach is to convert all
significant elements into equivalent noise temperature,
then add them up. There are some excellent sources
on the net to guide you through the process. See
for example
http://www.satsig.net/noise.htmAlso agilent
have an Application Note on the subject number 57-1
which can probably be downloaded from [url]hp.woodshot.com[/url]
_________________
At bottom, life is all
about
Sucking in and blowing out.
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Avalan |
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Post subject: Re: Microwave Noise
Posted: Sun Mar 29, 2009 2:37 pm
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Joined: Wed Mar 18, 2009
11:07 am
Posts: 2 |
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hi nubbage
thanks for the info, it answers
alot of my questions...
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Posted 11/12/2012
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